Foundry sand reducer and reclaimer

ABSTRACT

A foundry sand reducer and reclaimer using solely vibration to effect formation of individual grains and removal of substantially all organic matter coated on the grains.

United States Patent 11 1 1111 3,863,847 Day et al. Feb. 4, 1975 [54]FOUNDRY SAND REDUCER AND RECLAIMER [56] References Cited [75] Inventors:Wallace Day, Augusta; Alvin E. UNITED STATES PATENTS Postell, Martine lam D- Postel 2,020,800 11/1935 Royer 241/69 x Augusta, all of Ga.2,452,362 10/1948 Erisman 24l/DlG. IO 2,488,381 11/1949 Davies 209/234[73] Asslgneei CW8"! 3,709,441 1/1973 Hessner et al. 24l/263 Grovetown,Ga.

[22] Filed: July 26, 1973 Primary Examiner-Granville Y. Custer, Jr. ppNo: 382,789 gztitxzglexeAgent, 0r FzrmMason, Fenwrck &

[52] U.S. Cl 241/14, 241/24, 241/26, [57] ABSTRACT 241/29 241/69 241/791241/263 241/2731 A foundry sand reducerand reclaimer using solely vi.-

24l/DIG- 1O bration to effect formation of individual grains and re-[51] llil. Cl. B02C 19/20 moval of substantially all organic mattercoated on h [58] Field of Search 241/1, 14, 24, 26, 29,

241/30, 69, 79, 79.2, 94, 175, 262, 263, 273.1, 283, 284, DIG. 10;209/234 grains,

29 Claims, 8 Drawing Figures PATENTEB FEB 4I975 SHEET L 0F 4 FOUNDRYSAND REDUCER AND RECLAIMER The present invention relates generally to anapparatus and method for treating foundry sand. More particularly, thepresent invention is concerned with method and apparatus for thetreating of large lumps or chunks of foundry sand that previously formeda mold or core for the casting of metal parts including reducing thesize of the sand lumps to an individual grain size without significantlyfracturing the sand grains while removing substantially all bindermatter coating the grains.

BACKGROUND OF THE INVENTION In conventional foundry practice, the basicoperations for making sand molds or cores for metal castings include thepacking of the molding sand around the pattern and in the core box thatis used to shape the mold and core. In the molding operation, it isnecessary to force the sand around the pattern in order to achieveacurate castings without surface blemishes or defects. Thereafter, themetal is poured and followed by proper cooling, the casting may beremoved.

An important requirement in the sand casting operation is the mold andcore sand. This sand may be of various types dependent on the size andtype of the casting material. One type of sand in common use in foundrypractice is silica sand grains mixed with additives or other bindermaterials.

The binders, usually mixed with the sand, aid in holding the shape ofthe mold and core after the pattern or core box has been removed and addvarious other characteristics to the molds and cores.

The binders have historically included cereals; ground pitch; seal coal;gilsonite; fuel oil; wood flour, molasses; dextrin; core oil, which is amixture of linseed oil, resin, and thinner such as kerosene; corn flour;various protein binders, such as gelatin; casein; glue; coal tar; pitch;petroleum pitch; wood and gum rosin. In the past decade, foundrytechnology has introduced new binders replacing those mentioned above.These new binders form a chemical reaction in the mold. Among suchbinders are resins classified as furans, alkyds, urethanes, urea-, andphenol-formaldehydes. Also included are silicates such as sodiumsilicates and cement.

While the advantages of utilizing binders generally outweigh thedisadvantages, it is nevertheless important for the foundrymen to takecare in the use of the binders since they vaporize during the castingoperation and give rise to the possibility of gas bubbles causing pinholes and other inaccuracies in the casting.

The problem of vaporization is particularly acute upon attempted re-useof the sand after an initial mixture of the silica sand with the binder.Upon examination for reuse, some of the sand grains will be bare due tothe burning off of the organic material during the previous pour andtherefore, additional organic materials must be added for the re-use ofthe sand in the next molding cycle. while other grains will becompletely coated. When additional organic material is added to whatpreviously remained there is oftentimes produced a vaporization of theorganic material that is too great to be controlled and results in areject casting. When casting large pieces requiring days and weeks ofcooling. the economic loss is readily apparent.

The foundry practice is replete with methods and apparatus forattempting to reclaim the sand particles both as to coated matter on thegrains and the final size distribution of the sand particles. Previoustechniques attempted to remove as much of the organic matter coated onthe grains as is possible, but they failed in achieving a substantiallyorganic-free sand grain having not more than about 5 percent organicmaterial by weight remaining without destroying the desirable particlesize distribution which typically would allow about percent of the sandgrains to be retained upon 30 I00 mesh screens.

The reclamation of the sand as to size originally did not pose a severeproblem since the sand bound with the historically used bindersgenerally involved a shakeout operation which would produce loose sandwith perhaps only 5 percent lumps by weight. These lumps were found torequire little energy to degrade to individual grains due to the lowyield of the binding forces holding the binder coated sand grainstogether. Typical of this simplified sand reclaiming operations isDavies US. Pat. No. 2,488,381 in which superposed shakeout members wereused.

This low energy requirement for such old binder coated sands is instriking contrast to the high energy input the art found to be requiredto break up to tightly bound lumps and clumps of much larger sizeobtained from the use of the chemical reaction type binders. Theseextremely large chunks must be reduced to individual grain size to beuseful to the foundryman and to permit the removal of this current typeof binder from the sand.

The previously known methods of reclaiming the chemical reaction typebinder coated foundry sand utilize some form of impact grinding,crushing or blasting or other rigorous action which may ultimatelyremove much of the organic material coating from the grain of sand butcause more serious problems by reason of the fracture of the sandgranules due to the impact forces imposed upon the sand granule. Thefracture of the sand grain is a serious defect in foundry sand sincesize distribution uniformity of the molding sand is important inobtaining the permeability necessary for good casting operation. Thefracture of the sand grains forecloses the desirable gaseouspermeability of the mold by filling these interstices. The result isusually a rejected casting.

While it is recognized that sand grain size distribution must beretained, the use of impact or crushing forces heretofore had been apart of every reclaiming operation known in the art for reclaimingchemical reaction type binder coated sand. Vibration techniques and theuse of vibratory screens on the other hand are known and practiced butalways in combination with the use of sufficient impact or pressureforce that fractures the sand granule, rendering it substantially lessuseful than the desired uniform size sand grain.

OBJECTS OF THE INVENTION It is accordingly an object of the presentinvention to provide a method and apparatus for reclaiming sand andremoving substantially all of the binder matter previously mixed withthe sand grains.

Another important object of the present invention is to reclaim thefoundry sand and remove substantially all of the binder matter withoutfracturing the sand gram.

A further object of the present invention is the provision of method andapparatus for utilizing wholly vibration forces to reduce the largelumps of foundry sand into clean individual grains.

Another object of the present invention is the provision of a method andapparatus wherein vibration forces alone reduce the lump of foundry sandto individual grain size and also effect the abrading of one grain uponanother to remove the binder material from the grain.

This invention also has as an important object in the provision of anapparatus and method for maintaining a mass of sand grains in asubstantially unsupported state as in a fluidized bed whereinagglomerates of the sand grains are reduced in size and simultaneouslyindividual grains are abraded against each other to remove the bindermatter.

A further object of the present invention is the provision of apparatusand method for reducing and classifying the sand grains while removingorganic matter therefrom without fracturing the sand grains.

These and other objects of the present invention become 'readilyapparent upon a careful perusal of the specification including thedrawings.

THE DRAWINGS FIG. I is a perspective overall view of the apparatus andincluding an illustration of a cutaway of the spring supportingmechanism.

FIG. 2 is a perspective view partly exploded illustrating the topdisintegration zone, the scrubbing zone where the sand grains are insubstantially unsupported, fluidized state, the screening zone and thelowest or discharge zone. Included in this illustration also is aperspective view partly in section of an enlarged view of the slottedplate forming the scrubbing zone.

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. I andillustrating the entire operation for reducing and reclaiming foundrysand.

FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 3illustrating the vibration mechanism and mounting.

FIG. 5 is an enlarged view taken along lines 55 of FIG. 3 illustratingthe sawtooth arrangement in the disintegrating zone.

FIG. 6 is a fragmentary view partly broken away of the top zoneillustrating the spacers and sawtooth arrangement.

FIG. 7 is a fragmentary view partly broken away of the scrubbing zone.

FIG. 8 is an enlarged cross-sectional view taken along lines 88 of FIG.5, and partly broken away, illustrating the thickness of the teethforming the gripping means.

DESCRIPTION OF THE APPARATUS Referring to the drawing, FIGS. 1 through 4generally illustrate the reducer and reclaimer apparatus of the presentinvention.

In its broadest aspects the reducer-reclaimer may be composed of severalstages, or zones, as may be best seen in FIGS. 2 and 3. The first zone12 is designed to disintegrate the large lumps L of foundry sand inwhich the individual grains are bound together by a binder coating, suchas the usual resin binder that forms a chemical reaction in the mold.

The stage below the disintegrating stage is the scrubbing zone 14wherein the grains are vibrated into a fluidized or unsupported state.Below the scrubbing deck is a screening zone 16 through which theindividual grains pass and the large agglomerates or pieces of trappedmetal are retained. At 18 is shown the discharge zone wherein theindividual grains have been essentially cleaned and classified and arethen discharged.

The reducer-reclaimer is vibrated with a conventional motorized vibrator20 as shown in FIG. 4.

The reducer-reclaimer of the present invention in more specific detailis composed of a platform or base 22 composed essentially of channelmembers 24 which are interconnected by cross channel members 26 to formthe more or less rectangularly shaped platform or base 22. In FIG. 4,the centrally disposed cross channel member, 26, is extended beyond thelongitudinal channel iron 24 and supports vertical upright members 28suitably supporting a motor mount 30 which receives a conventionalmotor, 32. Conventional belts 34, drive an eccentrically weighted shaft36 which is positioned within housing 38 that is secured to front 40 andrear 42 walls forming a frame 44 of the reducer-reclaimer. The front andrear walls 40 and 42 are joined at their extremities by side walls 46and 48 to form in effect a box 49. The housing 38 is provided with aradial flange 50 on either end which is bolted to the respective frontand rear walls 40 and 42 and to apertured plates 52 and 54 on theoutside of the side walls. Suitable bearing mechanism not forming a partof the present invention may be retained between the flange 50 and theaperture plates 50 and its respective associated apertured plates 52 and54 to permit the rotation of the eccentric shaft 36. Eccentricallyweighted flywheel 56 is provided at the motor end of the shaft 36 tovibrate the box 49.

The frame 44 is supported directly by tubular cross members 58 spacedalong the channel members 24 as may be seen from FIG. 3 and secured tothe frame by a plurality of flanges 60 positioned on each side of thefront and rear walls, 40 and 42. At the location of the position of eachof the tubular cross members 58 on the exterior of the frame ispositioned a spring assembly including a support arm 62 having anupstanding rod 64. At the base of the rod 64 and resting upon thechannel member 24 is a spring seat 68 supporting a vertically disposedspring 70. At the upper end of the rod 64 is a collar 72 bearing againstthe spring and held in place with nut 74. The rod 64 as shown protrudesupwardly through an opening provided in channel number 24 as shown at 76and permits the spring seat 68 to be supported by the channel member 24around the opening 76. Housing 78 covers the spring assembly memberformed by the spring and its associated elements.

The disintegration zone, as may be best seen from FIGS. 2 through 6,includes a frame extension member 80 surrounding the upper portion ofthe reducerreclaimer to form a hopper. The extension is secured to theframe 44 in any suitable manner below the upper edge of the extension 80to house the disintegrating section or zone, 82. This disintegratingzone is composed of sawtooth blades 84 spaced as best shown in FIG. 6 byspacers 86 to maintain the blades 84 in position. The sawtooth bladesare welded and held in place by retaining plate 90 and clamped to angleirons 92 secured to the front and rear walls 40 and 42. As may be bestseen in FIG. 5, the teeth 94 are in alternate or staggered positionrelative to each other. The spacing between the teeth is approximatelyone-fourth inch, and the teeth are of a width at the apex 94a of aboutonehalf inch and at the base of the blade 94!), the blade narrows toapproximately three-eighths of an inch. The purpose for the tooth beingwider at the apex than the blade is at the bottom is to prevent any ofthe tramp metal or other large pieces from becoming lodged at a pointbelow the apex of the teeth.

The saw teeth are of a height preferably not less than 2 inches and formangles by their sides 95 of about 30 to 45 from the vertical to providesufficient area to contact and grip the lump L and cause itsdisintegration. A lower height of the teeth than 2 inches even flatcould be used but tends to reduce the efficiency in terms of tons ofsand per hour produced. The toothheight could be raised beyond 2 inches,perhaps to 3 inches or more but after the tooth height has been raisedbeyond the preferable range of 2 to 4 inches, the tramp metal that isusually present in the foundry sand removed from the mold would tend tobend the tips of the teeth. Most preferably, the tooth height has beenfound to be 2 V2 inches.

The large lumps 82 that are thrown into the hopper formed by the guard80 and on top of the sawtooth blades are disintegrated during thevibratory motion of the frame to grains or agglomerates of sand grainscoated with organic material ofa size approximately no larger thanone-fourth inch, which is the maximum spacing preferred between theteeth to obtain maximum efficiency but the precise spacing is not acritical feature.

The scrubbing zone 96 is one of the most important aspects of theinvention in that here the scrubbing of the particles takes place. Asshown, the scrubbing deck or decks 96 is composed of a plate or plates98 having a plurality of slots 100. The slots 100 of the scrubbing deckmay vary from one-thirtysecond to about threesixteenths and may bespaced from /2 to 2 inches apart.

Material passing through the scrubbing zone would generally be less thanone-eighth inch size and usually will be individual grains withsubstantially all of the binder matter removed due the fluidizing effectproduced by the scrubbing deck when in its vibratory motion.

The plate 98 is secured to the frame by being supported upon channelmembers 102 spaced across the apparatus as may be best seen in FIG. 3.

As the sand grains fall through the slots 100 they are impeded in theirtravel by the screen 104 forming the third or screening zone 106. Thescreen is supported on an incline as shown in FIG. 3 and is in a convexposition supported by screen support 108. The longitudinal edges of thescreen 104 are turned back as shown at 110 forming a hook which isengaged by a C-shaped retainer 112 that stretches the screen over thescreen support 108. Spring-biased rod 114 with the assistance of spring116 maintain the spring in tension along it longitudinal length. Thescreen 104 is preferably a twelve mesh screen which provides essentiallythe final classification that may be a screen size between mesh andmesh.

Due to the inclination of the screen 104 large agglomerates and trampmetal not passing through the screen 104 are discharged through chute118 in the sidewall 46.

After the sand grains fall through the screen 104 they are received uponauxiliary discharge pan 120 and discharge pan 122 that are inclined asbest shown on FIG. 3. The discharge pan may be a solid plate or may be ascreen between about and 250 mesh. The discharge chutes 120 and 122 areprovided with upstanding flanges 124.that are bolted to the front andrear walls. The sand is then discharged at 126 with substantially all ofthe binder removed.

THE METHOD In accordance with the method of this invention, the sandgrains are cleaned such that only 5 percent or less of binder matter byweight remains coated onto the sand grains but it is possible to removeeven greater amounts of the binder matter from the grains. It iscritical that in the present invention no impact or crushing force isapplied to the grains of sand and thus the uniformity of the originalsize distribution is maintained. In addition, the attrition of thecoating resulting from the vibratory motion creates round grains whichis desired in the foundry rather than the subangular particles producedby crushing.

The practice of the method is simply to place the large lumps L in thehopper and onto the sawtooth disintegration zone. At this time theentire frame is vibrating by reason of the rotation of the eccentricshaft 36. The vibration is preferably created by the shaft rotating atapproximately 1,000 RPM although speeds of from several hundred to 5,000or more rpm may be utilized. The vibration is preferably one producing avertical displacement of about one-fourth inch and a horizontalcomponent of about three-eights of an inch. The range may be fromone-eight to one-half inch vertical displacement and one-eighth tofive-eighths horizontal displacement. Such vibration is sufficient to beeffective for the purposes of.the present invention.

The dump of large lumps of foundry sand including tramp metal and otherimpurities is placed on top of the sawtooth blades 84. The saw teeth 94grip the large lumps and adjacent lumps not held by the teeth are freeto move against the large lumps so gripped. The result of the vibrationand the physical contact between the lumps is a disintegration of thelumps into agglomerates of grains of sand. Each agglomerate may be a fewto hundreds or more individual grains being bound by the binder whichmust be removed. Unlike prior art crushing or impact means for reducingthe size, of the lumps, the vibration in the disintegration zonefractures the lumps along the binder interface and not through thegrain.

As the individual grains are removed from the large lumps they passthrough the spacing between the blades 84 and fall to the scrubbing zone96 and onto the vibrating plate 98. Here the great mass of theagglomerates of the grains as well as individual grains are massed intoa bed that may be 1 inch to a foot in depth. Preferably the bed depth isabout 2 inches. By reason of the vibration, the grains are in anessentially continually unsupported condition which may be moredescriptively stated to be a fluidized state. This fluidized state is animportant aspect of the present invention because due to the unsupportedposition of a majority of the grains, the grains will hit each other intheir random motion and gently but effectively, after countless numbersof such mutual contacts among the irregular grains of sand with itsbinder coating, the grains will begin to 7 be cleansed of this coating.By maintaining the fluidizing state for from about 10 seconds to minutesbefore passing through the scrubbing zone, the grains will be not onlyfurther reduced from the agglomerates that may have existed but alsowill be scrubbed quite clean.

Through the use of the scrubbing deck alone, if there is sufficienttime, the grains will be cleansed to not more than 5 percent by weightof the binder coating. It is important therefore that to achieve thebenefits of the present invention, the vibrating be sufficientlyvigorous to maintain a fluidized or unsupported bed of the grains andthat the time in the scrubbing zone be sufficient to remove all thebinder matter desired. Preferably to 40 seconds is usually adequate. Nomaximum time except that which is dictated by commercial efficiency needbe placed upon the time the sand grains are in the scrubbing zone.

Gradually the sand grains will fall through the slots 100 and pass tothe screening zone. It should be understood, however, that the slots areonly provided to effect a simple means of passing the grains through tothe following zone. It is possible for the scrubbing plate or plates tobe continuous and without slots and inclined so that the grains willpass from an end of each plate to the succeeding plate or zone.

After the sand grains are passed through the scrubbing zone, they enterinto the screening zone 106 with screen 104 vibrating in the samemanner. The screen 104 again vibrates to maintain the particles in afluidized state to enable the individual grains to further removeadditional binder matter. The final screening or classifying is employedin order to produce usable foundry sand.

If in fact the scrubbing zone above removes all the required binder,then the screening zone would act principally as a sorting zone to trapand remove any of the tramp metal or other impurities that have passedthrough the other two zones and discharge those impurities and trampmetals out through the chutes 118.

The final discharge pan adds further vibration which may be adequate tofluidize the particles above and may aid in classifying the sand grainsfalling into this zone. The discharge pans may be screens of 100 to 300mesh or preferably 200 mesh, which meets the terms of the presentinvention. An air source, not shown, also preferably draws air throughopenings 128 and 130 over the discharge pans and out through theapparatus to remove any of the very light binder particles that havebeen abraded from the sand grains.

Another facet of this invention is the incorporation of all the requiredapparatus in a single unit that is simple and economical to operate.

We claim:

1. The method of reducing into individual grains, large lumps of foundrysand formed from sand grains coated with organic material and foundrybinders formed by chemical reaction in the mold and reclaiming thegrains into reusable foundry sand without impact forces sufficientlysevere to fracture the sand grains comprising:

vibrating said large lumps of foundry sand to produce agglomerates ofsand grains and individual grains in a first zone, passing said sandgrains to a second zone,

vibrating said grains in said second zone to maintain said grainssubstantially continually in an unsupported state, contactingsubstantially each of said 8 grains with adjacent grains while in saidunsupported state for at least 10 seconds to reduce the agglomerates toindividual grains by cleaving said agglomerates along the interface ofthe binder, and simultaneously abrading said grains with adjacent grainsto remove a sufficient amount of binder coated on said grains to permitcommercial foundry reuse, and

thereafter collecting said individual sand grains.

2. The method of claim 1 wherein:

said vibrating in said first zone includes the step of holding some ofsaid large lumps for vibrations with teeth in said first zone whileother large lumps are in rubbing contact with said first large lumps inorder to reduce the size of said lumps.

3. The method of claim 2 including:

said teeth being in a saw tooth arrangement.

4. The method of claim 1 including:

separating tramp metal from said large lumps during said vibration.

5. The method of claim 1 including:

providing openings in said first zone through which said grains pass tosaid second zone, said openings being of greater size adajcent saidsecond zone compared to the size in said first zone.

6. The method of claim 5 including:

providing a plurality of teeth in said first zone to hold said largelumps.

7. The method of claim 6 including:

vibrating said grains in said second zone from 10 seconds to 15 minutesbefore passing through said zone, screening said grains received fromsaid second zone to classify said grains.

8. The method of claim 1 including:

providing a plurality of teeth in said first zone to hold said largelumps.

9. The method of claim 1 wherein said vibrating in said first zoneincludes the step of holding some of said large lumps for vibration withteeth in said first zone while other large lumps are in rubbing contactwith said first large lumps in order to reduce the size of said lumpsand including separating tramp metal from said large lumps during saidvibration and providing openings in said first zone through which saidgrains pass to said second zone, said openings being of greater sizeadjacent said second zone compared to the size in said first zone.

10. The method of claim 1 including:

vibrating said grains in said second zone from 10 seconds to 15 minutesbefore passing through said second zone.

11. The method of claim 1 including:

maintaining said unsupported bed of said grains in said second zone forbetween 20 to 40 seconds.

12. The method of claim 1 including:

providing a plurality of openings in said second zone below said grainspermitting said grains to pass through said second zone.

13. The method of claim 1 including:

vibrating said grains in said second zone for at least 10 seconds tosubstantially remove all coated organic materials from said grains.

14. The method of claim 1 including:

screening said grains received from said second zone to classify saidgrains.

15. The method of claim 14 including:

screening said grains for at least 10 seconds.

16. The method of claim wherein: the time is about 2 5 minutes.

17. An apparatus for reducing the size of large lumps of foundry sandformed from sand grains coated with conventional foundry organicmaterials and reclaiming said grains by removing a substantial portionof said organic material from said grains without impact forces uponsaid lumps and grains, said apparatus comprising:

a base, a frame mounted on said base for vibratory movement relative tosaid base, vibratory means mounted on said base and connected to saidframe for vibrating said frame,

means connected to said frame and forming a first zone to reduce saidlarge lumps to smaller size by vibration,

means connected to said vibrating frame forming a second zone having abed for receiving the discharge from said first zone, said bed beingvibrated sufficiently by said vibratory means to produce a substantiallyunsupported mass of said grains in a fluidized state, whereby saidgrains are simultaneously abraded by adjacent grains to remove saidorganic material.

18. The apparatus of claim 17 including:

power means operable upon said vibratory means to vibrate said frame,said power means being positioned upon said base to form a unitaryapparatus.

19. The apparatus of claim 17 including:

spaced gripping means in said first zone to hold a first portion of saidlarge lumps whereby other large lumps are free to contact said firstportion of said large lumps.

' ping means having greater thickness in the direction of the first zoneand less thickness in the direction of the second zone.

21. The apparatus of claim 20 including: said gripping means being aplurality of upwardly extending teeth, said teeth being spaced a greaterdistance toward the discharge end of said first zone than at the top ofsaid teeth.

22. The apparatus of claim 19 including:

said gripping means being a plurality of upwardly extending teeth.

23. The apparatus of claim 22 including:

said teeth being spaced a greater distance toward the discharge end ofsaid first zone than at the top of said teeth.

24. The apparatus of claim 23 including:

said spacing being about one-fourth inch.

25. The apparatus of claim 17 including:

a discharge chute being a continuous solid plate with discharge at oneend.

26. The apparatus of claim 17 including:

said bed having a plurality of spaced slots through which said grainspass 27. The apparatus of claim 26 including:

said slots being about one-eighth inch in width.

28. The apparatus of claim 17 including:

a third zone having a screen connected to said vibrating frame forselectively separating said grains from tramp metals.

29. The apparatus of claim 28 including:

said screen having about a 12 mesh size.

1. THE METHOD OF REDUCING INTO INDIVIDUAL GRAINS, LARGE LUMPS OF FOUNDRYSAND GRAINS COATED WITH ORGANIC METERIAL AND FOUNDRY BINDERS FROMED BYCHEMICAL REACTION IN THE MOLD AND RECLAIMING THE GRAINS INTO REUSABLEFOUNDRY SAND WITHOUT IMPACT FORCES SUFFICIENTLY SEVERE TO FRACTURE THESAND GRAINS COMPRISING: VIBRATING SAID LARGE LUMPS OF FOUNDRY SAND TOPRODUCE AGGLOMERATES OF SAND GRAINS AND INDIVIDUAL GRAINS IN A FIRSTZONE, PASSING SAID SAND GRAINS TO A SECOND ZONE, VIBRATING SAID GRAINSIN SAID SECOND ZONE TO MAINTAIN SAID GRAINS SUBSTANTIALLY CONTINUALLY INAN UNSUPPORTED STATE, CONTACTING SUBSTANTIALLY EACH OF SAID GRAINS WITHADJACENT GRAINS WHILE IN SAID UNSUPPORTED STATE FOR AT LEAST 10 SECONDSTO REDUCE THE AGGLOMERATES TO INDIVIDUAL GRAINS BY CLEAVING SAIDAGGLOMERATES ALONG THE INTERFACE OF THE BINDER, AND SIMULTANEOUSLYABRADING SAID GRAINS WITH ADJAECNT GRAINS TO REMOVE A SUFFICIENT AMOUNTOF BINDER COATED ON SAID GRAINS TO PERMIT COMMERCIAL FOUNDRY REUSE, ANDTHEREAFTER COLLECTING SAID INDIVIDUAL SAND GRAINS.
 2. The method ofclaim 1 wherein: said vibrating in said first zone includes the step ofholding some of said large lumps for vibrations with teeth in said firstzone while other large lumps are in rubbing contact with said firstlarge lumps in order to reduce the size of said lumps.
 3. The method ofclaim 2 including: said teeth being in a saw tooth arrangement.
 4. Themethod of claim 1 including: separating tramp metal from said largelumps during said vibration.
 5. The method of claim 1 including:providing openings in said first zone through which said grains pass tosaid second zone, said openings being of greater size adajcent saidsecond zone compared to the size in said first zone.
 6. The method ofclaim 5 including: providing a plurality of teeth in said first zone tohold said large lumps.
 7. The method of claim 6 including: vibratingsaid grains in said second zone from 10 seconds to 15 minutes beforepassing through said zone, screening said grains received from saidsecond zone to classify said grains.
 8. The method of claim 1 including:providing a plurality of teeth in said first zone to hold said largelumps.
 9. The method of claim 1 wherein said vibrating in said firstzone includes the step of holding some of said large lumps for vibrationwith teeth in said first zone while other large lumps are in rubbingcontact with said first large lumps in order to reduce the size of saidlumps and including separating tramp metal from said large lumps duringsaid vibration and providing openings in said first zone through whichsaid grains pass to said second zone, said openings being of greatersize adjacent said second zone compared to the size in said first zone.10. The method of claim 1 including: vibrating said grains in saidsecond zone from 10 seconds to 15 minutes before passing through saidsecond zone.
 11. The method of claim 1 including: maintaining saidunsupported bed of said grains in said second zone for between 20 to 40seconds.
 12. The method of claim 1 including: providing a plurality ofopenings in said second zone below said grains permitting said grains topass through said second zone.
 13. The method of claim 1 including:vibrating said grains in said second zone for at least 10 seconds tosubstantially remove all coated organic materials from said grains. 14.The method of claim 1 including: screening said grains received fromsaid second zone to classify said grains.
 15. The method of claim 14including: screening said grains for at least 10 seconds.
 16. The methodof claim 15 wherein: the time is about 2 - 5 minutes.
 17. An apparatusfor reducing the size of large lumps of foundry sand formed from sandgrains coated with conventional foundry organic materials and reclaimingsaid grains by removing a substantial portion of said organic materialfrom said grains without impact forces upon said lumps and grains, saidapparatus comprising: a base, a frame mounted on said base for vibratorymovement relative to said base, vibratory means mounted on said base andconnected to said frame for vibrating said frame, means connected tosaid frame and forming a first zone to reduce said large lumps tosmaller size by vibration, means connected to said vibrating frameforming a second zone having a bed for receiving the discharge from saidfirst zone, said bed being vibrated sufficiently by said vibratory meansto produce a substantially unsupported mass of said grains in afluidized state, whereby said grains are simultaneously abraded byadjacent grains to remove said organic material.
 18. The apparatus ofclaim 17 including: power means operable upon said vibratory means tovibrate said frame, said power means being positioned upon said base toform a unitary apparatus.
 19. The apparatus of claim 17 including:spaced gripping means in said first zone to hold a first portion of saidlarge lumps whereby other large lumps are free to contact said firstportion of said large lumps.
 20. The apparatus of claim 19 including:said gripping means having greater thickness in the direction of thefirst zone and less thickness in the direction of the second zone. 21.The apparatus of claim 20 including: said gripping means being aplurality of upwardly extending teeth, said teeth being spaced a greaterdistance toward the discharge end of said first zone than at the top ofsaid teeth.
 22. The apparatus of claim 19 including: said gripping meansbeing a plurality of upwardly extending teeth.
 23. The apparatus ofclaim 22 including: said teeth being spaced a greater distance towardthe discharge end of said first zone than at the top of said teeth. 24.The apparatus of claim 23 including: said spacing being about one-fourthinch.
 25. The apparatus of claim 17 including: a discharge chute being acontinuous solid plate with discharge at one end.
 26. The apparatus ofclaim 17 including: said bed having a plurality of spaced slots throughwhich said grains pass
 27. The apparatus of claim 26 including: saidslots being about one-eighth inch in width.
 28. The apparatus of claim17 including: a third zone having a screen connected to said vibratingframe for selectively separating said grains from tramp metals.
 29. Theapparatus of claim 28 including: said screen having about a 12 meshsize.